I installed centos 4 very late into the release cycle for that version.

I'm looking to be an earlier adopter of Centos 5 (it just came out today) however, i can't risk a lot of downtime moving to the new system.

This is sort of a loaded question. I know the community works hard to make these releases available to us. But is it realistic to expect the initial release of a new release (in this case 5) to be stable and have the showstoppers worked out of it?